JPS642242Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in record players, and particularly to provide a record player suitable for using a microcomputer in its control circuit.

Recently, microcomputers have come to be widely used in various fields, and the present invention was developed to solve various problems when the microcomputers are applied to record players.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, the microcomputer itself is well known in various fields and does not require further explanation, so in this invention, we will explain the microcomputer by exemplifying a discrete circuit that achieves the same purpose. is mainly limited to input/output signals only.

FIG. 1 is a circuit block diagram showing an embodiment of the present invention, in which 1 is a microcomputer, 2 is a first photocoupler, and 3 is a circuit block diagram showing an embodiment of the present invention.
is the second photocabra, 4 is the third photocabra, 5
6 is a display circuit operated by the first output signal of the microcomputer 1 ; 6 is an auto-return signal generation circuit operated by the second output signal of the microcomputer 1 ; A tone arm drive mechanism that returns the arm to the rest position; 8 a lifter signal generation circuit that operates in response to the third output signal from the microcomputer 1 ; 9 a lifter that moves the tone arm up and down in response to the output signal of the lifter signal generation circuit 8; It is a mechanism.

The auto-return function of this invention optically detects the last silent groove on a record, processes the signal using a microcomputer or digital logic circuit, and drives an electrically operated tone arm drive mechanism to perform auto-return. It is something.

The final groove of 25cm and 30cm records has a radius of 57.6mm.
As mentioned above, the standard stipulates that the final sound groove of a 17cm record has a radius of 53mm or more. For that reason,
Uniformly determining the auto-return position causes inconvenience. For example, if you set the auto return position to 57.6mm, there is a risk that the auto return operation will start in the middle of the last song on a 17cm record, and if you set the auto return position to 53mm, the playback of the last song on 25cm and 30cm records will end. There is a risk that the auto-return operation will start after a while after it has stopped.

Therefore, in the present invention, a uniform auto-return position is not determined, but the auto-return position is set according to the state of the output signals of a plurality of photocouplers. Figure 2 A, A', B, C and D are model diagrams for explaining the auto-return function in detail.
is a turntable board, 11 is a turntable that rotates around axis 12, 13 is a tone arm,
14 is an armrest. The first photocoupler 2, which detects the difference in reflection between the silent groove (introductory groove, inter-track track, and lead-out groove) on the record surface and the recording groove, is placed at the tip of the tone arm 13. The second photocoupler 3 for detecting the size of records of different sizes is provided with a predetermined hole and is provided facing a reflector that rotates together with the tone arm 13. A third photocoupler 4, which generates a corresponding signal, is also provided facing the reflector. In detail, the arrangement of the first to third photocoupler 2 to 4 and the state of the reflector are as shown in FIG. 4. As shown in FIG. It is being The reflection plate 38 is fixed to the rotation shaft 39 of the tone arm 13, and
It rotates with. The reflecting plate 38 is provided with a first detection hole 40 at a position facing the second photocoupler 3 when the reflecting plate 38 rotates, and a second detection hole 40 at a position facing the third photocoupler 4.
and third detection holes 41 and 42 are bored.
However, the second detection hole 41 and the third detection hole of the reflection plate 38
A black printing 43 is applied between the detection hole 42 and a black printing 44 between the end of the first detection hole 41 and one end of the reflection plate 38. .

Further, substantially convex first, second, and third adjustment holes 45, 46, and 47 are bored at predetermined positions corresponding to the first detection hole 40 of the reflection plate 38, and the first, second, and third adjustment holes 45, 46, and First, second, and third adjustment members 48, 49, and 50 are arranged corresponding to the second and third adjustment holes 45, 46, and 47, respectively. and,
A convex fourth adjustment hole 51 is also bored at a predetermined position corresponding to the third detection hole 42.
A fourth adjustment member 52 is arranged corresponding to No. 1.

Therefore, when the tone arm 13 rotates in the direction of arrow A, that is, in the direction of arrow B in FIG.
According to the rotation, the position of the reflection plate 38 irradiated by the light emitting elements of the second and third photocoupler 3 and 4 changes. That is, the detection position of the second photocoupler 3 follows the position where the first detection hole 40 of the reflection plate 38 is drilled in accordance with the rotation of the tone arm 13, and the detection position of the third photocoupler 4 follows the position where the first detection hole 40 of the reflection plate 38 is formed according to the rotation of the tone arm 13. As the arm 13 rotates, the positions where the second and third detection holes 41 and 42 of the reflection plate 38 are drilled are traced. Since reflected light cannot be obtained from the hole portion of the reflector plate 38 or the black printed portion, the output signal level of the second and third photocoupler 3 and 4 changes depending on the detection position, respectively. Therefore, tone arm 1
3 in the direction of arrow B.
The photocoupler 3 and 4 generate output signals having waveforms as shown in FIG. 2 (b) and (c), respectively. In this case, the second photocoupler 3 is configured to generate an output signal for detecting the record size, and the second photocoupler ₃ is configured to generate an output signal for detecting the record size. The output signal is configured to change from "L" to "H" at the second position _D2 corresponding to the introduction groove or at the third position _D3 corresponding to the introduction groove of a 17 cm record.

The record size is detected using the second photocoupler 3, the first detection hole 40, and the first, second, and third adjusting members 48, 49, and 50.
Thus, the first adjustment member 48 determines the size of a 30cm record by its side 48a, the second adjustment member 49 determines the size of a 25cm record by its side 49a, and the third adjustment member 50 determines the size of a 25cm record by its side 49a. Side 5
The size of the 17cm record is determined by 0a.

By the way, in the tone arm device shown in Fig. 4, the position of the record stylus is on the inner circumferential side of the final tone groove of 30cm and 25cm records, which have the largest radius of the final tone groove among various standard records, and The output signal from the third photocoupler 4 changes from "H" to "L" within a predetermined range b on the outer periphery side of the last sound groove of a 17 cm record where the radius is the smallest.
Therefore, the output signal of the second photocoupler 3 is "H",
As is clear from FIGS. 2B and 2C, the output signal of the third photocoupler 4 becomes "L" only in a predetermined range a within a predetermined distance from the center of the turntable 11 shown in FIG. 2D. .

In addition, since the output signal of the first photocoupler 2 is "H" for the silent groove and "L" for the sound groove, in the case of a 17cm record by rotating the tone arm 13 in the direction of arrow B, the output signal is as shown in Figure 2 A. In the case of a 30cm record, the waveform is as shown in Figure 2 A'. In addition, 25
In the case of cm records, the position where the waveform corresponding to the introduction groove is generated is different, but in other parts
The waveform will be similar to that of a 30cm record, as shown in Figure 2 A'.

Therefore, the first, second and third photocoupler 2,
By using 3 and 4, it is possible to detect that the position of the record needle is within a predetermined range a from the center of the turntable 11 and that it has reached the silent groove. Moreover, the predetermined range a is 30 cm and 25 cm.
It is set within a predetermined range b on the inner circumferential side of the final tone groove of the record and on the outer circumference side of the final tone groove of a 17 cm record. Therefore, if the predetermined range a is set to, for example, the maximum radius of the last sound groove of 30 cm and 25 cm records, 57.6 mm, the position of the record needle will be 17 cm.
In the record, at the first position P ₁ , 30cm and
For 25cm records, the auto-return operation starts at the second position _P2 , and for the 17cm records, 30cm, and 25cm records, the auto-return operation starts immediately when the silent groove of the lead-out groove is reached.

By the way, in order to detect that the position of the record needle is within a predetermined range a from the center of the turntable 11, the output signal from the second photocoupler 3 is particularly used, so the output signal from the third photocoupler 4 is "L". ”, when the record stylus position has not reached the silent groove of the record due to noise etc., and the output signal of the first photocoupler 2 becomes “H”, the auto return operation may be performed by mistake. It is possible to prevent this from happening.

FIG. 3 shows an example of signal processing. In FIG. 3, 15 is a first signal detection circuit including a first photocoupler 2 and a waveform shaping circuit, and 16 is a second signal detection circuit including a second photocoupler 3 and a waveform shaping circuit. a second signal detection circuit; 17, a third signal detection circuit including a third photocoupler 4 and a waveform shaping circuit; 18, an inversion circuit for inverting the output signal of the third signal detection circuit 17;
9 is a first AND circuit that calculates the output signal of the inverting circuit 18 and the output signal of the second signal detection circuit 16; 20 is a first AND circuit that calculates the output signal of the first signal detection circuit 15 and the output signal of the first AND circuit 19; The first time to calculate
It is a 2AND circuit. By using the circuit shown in FIG. 3, the output signal of the first photocoupler 2 becomes "H",
Only when the output signal of the second photocoupler 3 becomes "H" and the output signal of the third photocoupler 4 becomes "L" can a control signal be obtained and the auto-return operation can be started.

Although the circuit block diagram in FIG. 3 has been explained in an easy-to-understand manner, the same operation can be achieved by using a microcomputer. Further, the signal obtained at the output terminal 21 in FIG. 3 is applied to the auto-return signal generating circuit 6 in FIG. 1, and the auto-return mechanism 7 is operated, but the auto-return signal generating circuit 6 is omitted. , the auto-return mechanism 7 may be directly driven by the signal obtained at the output terminal 21.

In addition to the above, the present invention is ideal for use in record players using microcontrollers, and in particular,
With various standard records, when the position of the record needle reaches the silent groove of the lead-out groove, the auto-return operation can be started immediately, and with 17cm records, the auto-return operation can be started in the middle of a song. Can be prevented with 30cm
Also, it is possible to prevent the inconvenience that the auto return operation starts some time after the last song of a 25cm record ends.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention.
Figure 2 A, A', B, C and D are waveform diagrams and model diagrams to explain the auto-return operation, and Figure 3
The figure is a block diagram showing an example of the circuit configuration for achieving the auto-return operation shown in Fig. 1, and Fig. 4 is a plan view showing the tone arm device to show the arrangement of the first to third photocoupler and the state of the reflector. be. Explanation of main drawing numbers, 1 ...Microcomputer, 2, 3, 4
... Photo converter, 5 ... Display circuit, 6 ... Auto return signal generation circuit, 8 ... Lifter signal generation circuit.

Claims (1)

[Scope of utility model registration request] In a record player having an auto-return mechanism at the end of playing a standard record, the position of the record needle is on the inner circumferential side of the final tone groove of the standard record whose radius of the final groove is the largest among the various standard records, and a first detecting means for detecting that the radius of the final tone groove is within a predetermined range on the outer circumferential side of the final tone groove of a standard record having a minimum radius; and detecting that the record needle is located in a silent groove of the record. a second detecting means, when the first detecting means detects that the sound is within the predetermined range and the second detecting means detects a silent groove of the record, the automatic return mechanism A record player characterized in that it generates a control signal to perform an auto-return operation.